This invention pertains principally but not exclusively to the use of liquid color in plastic molding and extrusion. The patent application even more specifically pertains to a multiple plate quick disconnect sandwich assembly preferably, but not necessarily, utilized with a liquid color pump installed on and forming a part of the lid of a liquid color container.
Pumps for liquid color are known, with one such pump being disclosed in U.S. Pat. No. 7,416,096, with another being disclosed in U.S. Pat. No. 7,980,834, and yet another being disclosed in U.S. Pat. No. 8,800,821. The disclosures of the '096, '834, and '821 patents are hereby incorporated by reference.
'096 discloses a container for liquid color material having a diaphragm liquid color pump located in the container for pumping liquid color from the container. The diaphragm liquid color pump is located in the container at the container bottom, where the pump can collect liquid color as the container empties. The pump is driven by a pneumatic piston-cylinder combination located outside the container, with a shaft extending downwardly from the pneumatic piston-cylinder combination to the diaphragm pump, to reciprocate the diaphragm back and forth to effectuate pumping action.
The '096 apparatus is relatively low in cost. The apparatus includes a liquid-tight fitting allowing liquid color output from the pump to be supplied directly to a plastics material processing machine, namely a molding press or an extruder, for the liquid color to impart color directly to plastic parts as they are manufactured.
The '834 apparatus provides pressure boosting, permitting liquid color to be injected into an extruder screw or a molding machine screw barrel at a position downstream, close to the position at which the finished plastic parts are molded or extruded.
'821 discloses a disposable low-cost pump in a container for liquid color, where the pump is fabricated from a plurality of PVC tubular members connected in a way to provide a pumping chamber. A piston is displaceable into the pumping chamber. A spring biases the piston outwardly from the chamber, in opposition to force applied by an air cylinder.
While these devices have merit and have proved commercially successful, there is a continuing need for lower cost, higher reliability quick connection apparatus to connect conduits to pumps and the like to provide liquid color from liquid color containers to injection and compression molding machines and to extruders, to color plastic parts in the course of manufacture thereof.